Elevator safety device.



PATENTBD MAR. 3, 1903.

W. N. MARTIN. ELEVATOR SAFETY DEVICE. APPLIU'ATION FILED MAR. 10 1902.

4 SHEETS-SHEET l.

' N0 MODEL.

WITNESSES.-

A TTORNEY.

rut wonms PETERS co. Puma-mac" wAsHmomu, u c

No. 721,816. PATENTED MAR. 3, 1903.

W. N. MARTIN.

ELEVATOR,SAFBTY DEVICE.

EPPLIGATION PILED KAB. 10, 1902.

N0 MODEL. I 4 $HEETS-SHEET 2.

WITNESSES.-

V ATTORNEY.

' No. 721,816. I PATENTED MAR.3, 1903.

- W. N. MARTIN.

ELEVATOR SAFETY DEVICE.

, APPLICATION FILED Mn. 10, 1902. 'No MODEL. 4 SHEETS-SHEET a.

WWII? WITNESSES JNVEZVTOR. Q

mm P'TERS co PHOTO-UTHO wnsmwcmxuc.

r v v No. 721,816. PATENTED'MAR; 3,1903.

' W. N. MARTIN.

ELEVATOR SAFETY DEVICE.

APPLICATION FILED MAR. 10, 1902.

4 SHEETS-SHEET 4.

10 MODEL.

EEEEV .l

imlulll r WHVNESSES;

urns wmumown n a UNITED STATES PAT T OFFICE.

WALTER N. MARTIN, OF ORIPPLEOREEK, COLORADO, ASSIGNOR OF ONE-. HALF TOJAMES T. STEWART, OF ORIPPLEOREEK, COLORADO.

ELEVATOR SAFETY DEVICE.

SPECIFICATION forming part of Letters Patent No. 721,816, dated March 3,19 03.

Application filed March 10. 19oz. Serial no. 97,625. (NomodeLl IF 0 allwhom, it may concern.-

Be it known that I, WALTER N. MARTIN, a citizen of the United States ofAmerica, residing at Oripplecreek, in the county of Teller and State ofColorado, have invented certain new and useful Improvements in ElevatorSafety Devices; and I do declare the follow ing to be a full, clear, andexact description of the invention, such as will enable others skilledin the art to which it appertains to make and use the same, referencebeing had to the accompanying drawings, and to the letters and figuresof reference marked thereon, which form a part of this specification.

My invention relates to improvements in elevator safety devicesgenerically, but will be referred to in this specification moreespecially as applied to cages for mining-shafts, where accidentsfrequently occur, resulting in the dropping of the cage to the bottom ofthe shaft, generally with fatal result to those on the cage andsometimes to others below in the shaft. My object is to preventaccidents of this kind not only in connection with mine cages, butelevators of all kinds as well. To avoid surplusage and awkwardness ofconstruction, the term cage will be used generally in this specificationas a generic term for cages and elevators of all kinds, Whether used inmining-shafts, building-shafts, Orelsewhere.

My improvements embrace features whereby as soon as the cable supportingthe cage breaks or the pull thereon is released or for any reason ceasesto act or perform its normal function clutch mechanism is automaticallyand instantly applied to the guides of the shaft with sufficient forceto stop the cage.

Having briefly outlined the nature of my improvement, as well as theobjects it is designed to attain and the functions it is intended toperform, I will proceed to describe the same in detail, reference beingmade to the accompanying drawings, in which is illustrated anembodimentthereof.

In the drawings, Figure 1 is aside elevation, partly in section, 'of acage equipped with my improvements. Fig. 2 is a section taken on theline 00 m, Fig. 1, looking downward. Fig. 3 is a view of the cage, takenat right angles to Fig. 1, the guide being partly broken away. Figs. 4,5, and 6 are side, face, and top views, respectively, of one of theupper dogs, being that which swings outwardly toward the guide. Figs. 7and 8 are side and top views, respectively, of an upper dog, which actslaterally on the guide or at right angles to the dogshown in Figs. 4, 5,and 6. Figs. 9 and 10 are face and side views, respectively, of a lowerdog. Figs. 11 and 12 are enlarged detail views, partly in section, ofthe dog shown in Figs. 7, 8, and 9, Fig. 12 being a section taken on theline jj, Fig. 11. Fig. 13 is a section taken through the parts connectedwith the draw-bar, which is shown in elevation. Fig. 14 is a sectiontaken through the levers, illustrating one of the weights, which isshown .partly in section. Fig. 15 illustrates two levers and theirweights, the position of the draw-bar being shown in dotted lines. Fig.16 illustrates a modified form of lever construction, showing adifferent construction and arrangement of Weights.

The same reference characters indicate the same parts'in all the views.7 V

Let the numeral 5 designate two opposite side timbers of a shaft, towhich are attached on the inside the vertical guides 6 for thecross-head, composed of two separated plates 7 whose extremities projecton opposite sides of the shaft-guides. The bottom 8 of the cage isconnected at the sides with the cross-head by vertical channel-bars 9,which inclose the guides on three sides. At a suitable distance from theopposite extremities of the crosshead are mounted two short shafts orspindles 10, provided with collars 10, engaging the plates 7 of thecross-head on the inside, whereby the two plates are held securely inplace against inward movement. On these shafts 10 are fulcrumed twolevers 12, whose arms extending inwardly from their fulcrums overlapeach other and are pivotally connected with a central vertical draw-bar13, having plates 14 on opposite sides, to which the lever-arms arerespectively connected by studs 15, mounted on the plates and passingthrough slots 12 formed in the levers. The cagesupporting cable (notshown) is connected with this draw-bar at the top. The upper extremityof this draw-bar passes through an inverted-U shaped guide-bracket16,attached to the plate 7 of the cross-head and having an opening inthe top for the bar, which also projects below the cross-head and passesthrough an opening in a guide-plate 17, attached to and connecting thelower edges of the crosshead plates. The extremity of this bar below theplate 17 is provided with a cross-pin 18, passing through an openingformed in the bar and held in place by collars 18 on opposite sides.This pin 18 normally engages the plate 17 when the cage is suspended bythe cable in the ordinary way, the weight of the cage being on the pin18 rather than on the levers 12. In the arrangement shown in thedrawings, however, it is taken for granted that the cable is broken, theparts being shown in the position they automatically assume to preventthe cage from falling in case of an accident of this character. In thisevent the draw-bar moves downwardly with the overlapping arms of thelevers, so that the pin 18 is considerably below the plate 17 of thecross-head. Each lever is provided with a set of weights 19, mounted onits inner arm. The draw-bar is connected with each lever between itsfulcrum and the Weights which straddle the lever-arms, one set ofweights being made fast to one lever and the other set of weights to theother lever by setbolts 20. Each lever is connected with the plate 17 bya coil-spring 21, which is stretched or placed under tension when thecage is suspended by its cable.

The short arm 12" of each lever 12 projects outwardly beyond theleverfulcrum to a point near the guide 6 and is slotted, as shown at 12,to receive the upper arms 22* of two dogs 22, pivotally mounted onplates 23, secured to the opposite sides of the cross-head extremities.As shown in the drawings, each dog is pivoted on lugs 23, formed on itsplate 23, and the lever-arm 22 below the axis, fulcrum, or pivot of thedog projects through an opening formed in the plate and is provided withteeth which normally or when the cage is suspended by the cable areclear of the guides 6, but occupy a. position quite close thereto. When,however, the cable breaks, the toothed faces of these dogs are thrownagainst the opposite sides of the guide to stop the cage from falling.To facilitate the action of the dog on the guide, the lowermost tooth 22is slightly longer than the other teeth of the dog. By reason of thisconstruction the dog will take a quicker hold than if all the teethengage simultaneously, and before the entire strain or weight of thecage can act on this tooth the teeth on the entire face of the dog willhave engaged the guide. It will now be understood that two dogs 22 graspthe guide 6 simultaneously on opposite sides. In order to overcome anytendency of the guide-bar 6 to spring or spread outwardly, owing to thepowerful thrust of a pair of inner dogs 24, the teeth of the dogs 22 aredirected inwardly as well as downwardly. This feature is indicated inFigs. 8, 9, and 12, in

which the teeth on the face of the dog are shown triangular in shape.

Each lever 12 is provided with a depending arm 12, located near itsouter extremity and slotted to receive a pin 25, upon which the dog 24is pivoted. This dog 21 is located between the arm 12 and the guide 6,and its face or the side adjacent the guideis toothed to engage theguide to prevent the cage from falling. The toothed face of the dog 24,however, is normally or when the cage is suspended and held by the cablefree from engagement with the guide. In case the cable breaks theweights 19 and the springs 21 cooperate to throw the inner lever-armsdownwardly, whereby the dogs 24: are thrust with great force outwardlyagainst the guides. The lever-arm 12 bears against the back of the dogand has a cam action thereon to relieve the pin 25 from strain duringthe aforesaid action of the lever 12. The dogs 24 are forced powerfullyout against the guides 6 simultaneously with the lateral thrust of thedogs 22. The tendency of the dogs 24 is to thrust the guides outwardly,while the dogs 22, by virtue of the peculiar shape of their teethalready described, whereby they project inwardly, are intended toovercome this tendency.

Pivotally mounted on brackets 26 and secured to the channel-bars 9 belowthe bottom of the cage are dogs 27, having toothed faces 27, projectinginwardly toward the guides 6, which they are arranged to engage onopposite sides to prevent the cage from falling. The lowermost tooth ofeach of these dogs is somewhat longer than the other teeth, for thepurpose above stated, when speaking of the dogs 22. This is also true ofthe lowermost teeth of the dogs 24. The toothed arms of the dogs 27project below their pivots 28. These dogs are also provided withinwardlyprojeeting arms 27, whose free extremities are bifurcated orforked to straddle the crosspin mounted on the lower extremity of a rod29, whose upper extremity is connected with the arm 12 of a lever 12 atits outer extremity, whereby as the inner arms of the levers 12 arelowered and their outer arms raised the rods 29 (there being one on eachside of the cage) will be raised snfiiciently to throw the dogs.27 tooperative engagement with the guides 6 simultaneously with thecorresponding action of the upperdogs 22 and 24. It is evident thatother dogs intermediate the upper and lower dogs, already described, maybe mounted on the channel-bars of the cage and connected with the rod 29to be operated thereby in the same manner as the dogs 27.

In this specification it is assumed that the guides 6 are composed ofwood, which is the fact in mining-shafts. Hence the teeth of the metaldogs readily enter the wood to perform their required function. It isevident, however, that the guides may be equipped with metalratchet-bars arranged to cooperate with the dogs carried by the cage.

As shown in the drawings, the hubs of the dogs 22 and 27 are equippedwith grease-cups A and are interiorly enlarged, as shown at B, to form areceptacle for packing material, as waste saturated with lubricant.

From the foregoing description the use and operation of a cage equippedwith my improved safety devices will be readily understood. When thecage is in use in the ordinary way, these devices perform no function,the inner arms of the levers 12 being raised by the draw-bar, which isdrawn upwardly by the cable, so that the cage-supporting pin 18 shallengage the guide-plate 17 at the bottom of the cross-head. The outerextremities of the levers are then in position to hold all the dogs,both upper, lower, and intermediate, (if the latter are employed,) awayfrom the guides 6, so that the cage is allowed to move freely in theshaft in the same manner as if the safety equipment were absent. If,however, the cable breaks or any other accident gaging the shaft 10 onopposite sides of the lever. The hubs, as shown in the drawings, areequipped with grease-cups and may be interiorly recessed to receivepacking material,the same as the dogs heretofore described.

The sides of the dogs 24 are grooved, as

. shown at 24 to en a e horizontal ton ues of 9 a b b guides 7,interiorly mounted on the opposite plates of the cross-head 7.

In the construction shown in Fig. 16 a modified form of lever is shownand designated 12. One extremity of this lever is arranged to holdweights 19, held in place by a bolt 20, suitably secured by a nut at thetop.

Having thus described my invention, what I claim is 1. In safetymechanism for cages or elevators, the combination with thevshaft-guides, of a cage cross-head composed of two separated plates, andhaving parts embracing the shaft-guides, spindles mounted on thecrosshead between the said plates and provided with collars engaging thetwo plates on the inside to keep them suitably spaced, levers locatedbetween the two cross-head plates and fulcru med on the said spindles, adog pivotally mounted on the cross-head on each side of eachshaft-guide,the guide-embracingparts being cut away to allow the dogs tobite the guides, a suitable operative connection between the outer armof each leverand the said dogs, a draw-bar vertically movable on thecross-head and connected with the inner arms of the levers, guidesmounted on the cross-head through which the bar passes, a

cross-head whereby as the lifting pull on the draw-bar ceases to act,the levers are actuated to cause the dogs to bite the shaft-guides,substantially as described.

2. In mechanism of the class described, the combination withshaft-guides,of a cage crosshead composed of two separated parts,spindles mounted on the cross-head plates, levers fulcru med on thespindles between the plates,

a draw-bar connected with the inner extremities of the levers and havinga stop at its lower extremity, said stop engaging the crosshead when thecage is suspended from the draw-bar, the outer extremities of thecrosshead having parts embracing the shaft-guides, dogs pivotallymounted on said parts which are cut away to allow the dogs to engagesaid guides, the outer arms of the levers being slotted,the dogs havingarms projecting above their pivots and entering the slots of the levers,the draw-bar having sufficient movement in the cross-head, to throw thedogs into or out of engagement with the shaft-guides, and coil-springsconnected at one extremity with the inner arms of the levers and attheir opposite extremities with the cross-head, the springs being placedunder tension when the cage is suspended by the cross-head.

3. In safety mechanism for cages or elevators, the combination with theshaft-guides, of a cage cross-head composed of two separated plates, twolevers fulcrumed between the plates, a cage draw-bar connected with theinner arms of the levers, the outer arms of the levers being slotted,the cross-head having parts engaging the shaft-guides on opposite sides,a dog pivotally mounted on each of said parts which iscut away to allowthe dogs to bite the guides, the dog on each end of the cross-headhaving arms projecting through the slot of the adjacent lever, andsprings connected with the inner arms of the levers and placed undertension when the cage is suspended by the draw-bar.

4. In safety mechanism for cages or elevators, the combination with theshaft-guides, of a cage or elevator cross-head composed of two separatedplates having parts embracing the shaft-guides on opposite sides, adrawbar mounted on the cross-head and having a limited vertical movementtherein, levers fulcrurned between the cross-head parts, three dogsmounted'on the shaft-guide-engaging parts at each extremity of thecross-head, the said parts being cut away to allow the dogs to bite theguides, the three dogs being con-' nected with the outer arm of theadjacent 1ever, whereby as said arm is moved upwardly,

IIO

the dogs are caused to bite the guide, and means connected with theinner arms of the levers for throwing the latter downwardly as soon asthe pull on the draw-bar ceases to act.

5. In safety mechanism for elevators or cages, the combination with theshaft-guides, of a cross-head composed of two separated plates havingparts at their extremities engaging the shaft-guides on three sides, adog slidable horizontally in each extremity of the cross-head, theguide-embracing part on the inside being cut away to allow the dog toengage the guide, two levers fulcrumed between the cross-head plates,springs connecting the levers with the cross-head, a draw-bar connectedwith the inner arms of the levers and slidable vertically in thecross-head, whereby when the cage is suspended by the draw-bar thesprings are placed under tension, the outer arm of each lever beingconnected with the dog to actuate the latter as the inner arms of thelevers are operated by the recoil of the springs when the pull on thedraw-bar ceases to act.

6. In safety mechanism for elevators or cages, the combination with theshaft-guides, of a cross-head composed of two separated plates whoseextremities embrace the shaftguides, a draw-bar, upper and lower guidesmounted on the cross-head and through which the draw-bar passes and inwhich it has a limited vertical movement, a plate attached to each sideof the draw-bar, levers fulcrumed on the cross-head and whose inner armsare pivotally connected with the said plates,

springs connecting the inner arms of the levers with the cross-head andplaced under tension when the cage is suspended by the cross-head, anddogs mounted on the crosshead and connected with the outer arms of thelevers whereby the dogs are actuated to grip the shaft-guides when thelevers are operated by the recoil of the springs.

7. In safety mechanism for elevators or cages, the combination with theshaft-guides, of a cross-head composed of two separated plates havingupper and lowerguides mounted on the cross-head, a draw-bar passingthrough said latter guides and having 2. limited movement therein,levers fulcrumed between the plates of the cross head, dogs mounted onthe cross-head extremities and connected with the outer arms of thelevers to grip the shaft-guides when the inner arms of the levers areforced downwardly, the inner arms of the levers being connected with thedraw-bar, and weights mounted on the inner arm of each lever,substantially as described.

8. In safety mechanism for elevators or cages, the combination with theshaft-guides, of a cross-head composed of two separated plates whoseextremities engage the shaftguidcs, dogs mounted on the cross-headextremities, levers fulcrumed on the cross-head and whose outer arms areconnected in operative relation with the dogs, a draw-bar having limitedvertical movement in the cross-head and connected with the inner arms ofthe levers, springs connecting the inner arms of the levers with thecross-head, dogs mounted on the cage below the cross-head and adjacentthe shaft-guides, and rods connecting the outer arms of the levers withthe dogs in operative relation substantially as described.

9. In safety mechanism for elevators or cages, the combination with theshaft-guides, of a cross-head, a guide mounted on the crosshead, adraw-bar passing through said guide and having a limited movementtherein, levers fulcrumed on the cross head, dogs mounted on thecross-head extremities and connected with the outer arms of the leversto grip the shaft-guides when the inner arms of the lovers are forceddownwardly, the inner arms of the levers being connected with thedraw-bar, and weights mounted on the inner arm of each lever, theconnection between the lever and draw-bar being between thelever-fulcrum and the weights.

10. In safety mechanism for cages or elevators, the combination with theshaft-guides, of a cage or elevator cross-head having parts embracingthe shaft-guides on opposite sides, a draw-bar mounted on thecross-head, and having limited vertical movement therein, leversfulcrumed on the cross-head, three dogs mounted on the shaft-engagingparts at each extremity of the cross-head, the said parts being cut awayto allow the dogs to bite the guides, the three dogs being connectedwith the outer arm of the adjacent lever, whereby as the said arm ismoved upwardly the dogs are caused to bite the guide, and meansconnected with the inner arms of the levers for throwing the latterdownwardly as soon as the pull on the draw-bar ceases to act.

11. In safety apparatus for elevators or cages provided with a topcross-head, of dogs mounted thereon in proximity to the shaftguides,there being one dog adjacent the inner surface of the guide and two dogslocated adjacent the respective side surfaces of the guide, the dogshaving teeth arranged to bite the guides as described, the teeth of theside dogs projecting inwardly to prevent the spreading of the guides,levers fulcrumed on the cross-head and connected with the dogs tooperate the latter, and a draw-bar slidable on the cross-head andconnected with the levers, substantially as described.

In testimony whereof I aflix my signature in presence of two witnesses.

WALTER N. MARTIN.

Witnesses:

S. A. PHIPPs, J. D. PUTMAN.

IIO

